Fig. 2.

(a) Luminol-derived chemiluminescence of extracellular H₂O₂ release in BALB/c and non-obese diabetic (NOD).H2^h4 mouse thyrocytes. Single-cell suspensions from thyroid glands of 12–14 mice per group were prepared and stimulated with iodine. All samples were run in parallel, and results were compared with the no sodium iodide (NaI) control groups. Constitutively expressed levels of H₂O₂ release were noted in NOD.H2^h4 mice that increased further after iodine addition. In contrast, levels of H₂O₂ release from BALB/c remained remarkably low at all times (representative of two separate experiments). (b) Intracellular reactive oxygen species (ROS) detection in the thyrocytes of B10.A (upper panel) and NOD.H2^h4 mice (lower panel). Thyrocytes were stimulated in vitro with phosphate-buffered saline, phorbol 12, 13-dibutyrate (PDBu) or NaI. Thyrocytes of NOD.H2^h4 but not of B10.A mice produced a spike in the level of ROS in response to iodine addition. Shown are 36·58% of thyrocytes from NOD.H2^h4 mice and 7·61% of B10.A mice producing ROS (representative of three experiments).